In a vehicle provided with a curtain airbag device, when the vehicle is involved in, for example, a side-on collision or rollover, curtain airbags are deployed downward along inner side surfaces (for example, doors and pillars) of the vehicle cabin so as to protect the head of each vehicle occupant and to keep each vehicle occupant inside the vehicle cabin.
U.S. Pat. No. 6,237,938 discloses an example in which a guiding element is disposed along a C pillar. Specifically, such a guiding element is provided for guiding a rear portion of a curtain airbag, which is inflatable along an inner side surface of a vehicle cabin, in the downward direction along pillars.
The guiding element according to U.S. Pat. No. 6,237,938 includes a track member having a box-shaped cross-section, and a slider which is disposed within the track member and is movable in the longitudinal direction of the track member. A tether (cord) extending from the rear portion of the curtain airbag is tied to the slider. When the curtain airbag is to be deployed downward, the tether pulls the slider so that the slider is shifted downward along the track member. For preventing the rear portion of the curtain airbag from being retracted upward after being moved downward, the track member is provided with latches, which are disposed at a regular interval substantially along the entire length of the track member.
The top and bottom ends of the track member are provided with mounting flanges. Each of the flanges is fixed to the C pillar with a bolt or a screw.
On the other hand, according to Japanese Unexamined Patent Application Publication No. 11-91490, an overhang member projected towards the interior of a vehicle cabin is provided. Specifically, such an overhang member allows the curtain airbag to jump over an upper end of a pillar garnish during the deployment process of the curtain airbag so as to guide the curtain airbag towards the interior of the vehicle cabin.
Furthermore, Japanese Unexamined Patent Application Publication No. 2002-347560 and Japanese Unexamined Patent Application Publication No. 2003-81048 each disclose a curtain airbag device in which the rear portion of an inflated curtain airbag is pulled backward with a rope so that a strong tension is created along a lower line of the curtain airbag.
According to the curtain airbag device of U.S. Pat. No. 6,237,938, when the downward deployment process of the curtain airbag is started and the base end of the tether is pulled downward by the curtain airbag, the downward movement of the front end of the tether may be held back due to a frictional force generated between the slider and the track member. This may possibly inhibit a smooth deployment process of the curtain airbag.
On the other hand, in Japanese Unexamined Patent Application Publication No. 11-91490, the lower portion of the deploying curtain airbag cannot be drawn in towards the inner side surface of the vehicle cabin.
In Japanese Unexamined Patent Application Publication No. 2002-347560 and Japanese Unexamined Patent Application Publication No. 2003-81048, if an interior cover, such as an interior trim panel, is present inside the vehicle cabin, it is extremely difficult to set up a rope due to limitations of space.